1. Field of the Invention
The invention relates to the field of milking and more particularly to a device for automatically milking an animal.
2. Description of the Related Art
Devices are known for automatically milking dairy animals. Such devices may be provided with at least two teat cups for connection to respective teats of the animal and a milking vacuum unit for generating a milking vacuum in the teat cups. The milking vacuum unit may comprise at least two vacuum lines that are each connectable to a respective teat cup.
A device is known from DE-A1-3609275, the contents of which are hereby incorporated by reference in their entirety, by means of which animal-dependent or udder quarter-dependent milking is possible.
The invention aims inter alia at providing an alternative and improved device for automatically milking an animal.
For this purpose, according to the invention, a device for automatically milking an animal of the above-described type comprises at least two teat cups for connection to respective teats of the animal and a milking vacuum unit for generating a milking vacuum in the teat cups, the milking vacuum unit comprising at least two vacuum lines that are each connectable to a respective teat cup, a common vacuum pump, a common buffer vessel to which vacuum can be applied by means of the common vacuum pump, the at least two vacuum lines being connectable to the common buffer vessel, an individual buffer vessel in each vacuum line disposed between the common buffer vessel and the respective teat cup and being connectable to the common buffer vessel by a first vacuum line portion and being connectable to the respective teat cup by a second vacuum line portion, and an individual vacuum pump for each individual buffer vessel for applying vacuum to the respective individual buffer vessel. Due to the fact that the milking vacuum unit comprises both a common vacuum pump and an individual vacuum pump per individual buffer vessel, it is possible to apply a milking vacuum per teat cup in an accurate and reproducible way.
It is in particular advantageous if the common vacuum pump for applying vacuum to the common buffer vessel is a frequency-controlled vacuum pump.
For the purpose of providing a vacuum pressure with an accurate value, in an embodiment of a device according to the invention, a vacuum sensor for measuring the vacuum is included in the common buffer vessel. The common vacuum pump can preferably be controlled with the aid of data from the vacuum sensor for measuring the vacuum in the common buffer vessel.
In an embodiment of a device according to the invention, an individual buffer vessel has an upper side, in which an air inlet control valve is disposed. Moreover, an individual buffer vessel may be provided with a vacuum sensor for measuring the vacuum in the individual buffer vessel. For obtaining an accurate milking vacuum, an individual vacuum pump or the air inlet control valve can be controlled with the aid of data from the vacuum sensor for measuring the vacuum in the individual buffer vessel.
For generating a correct milking vacuum the dimensions of the vacuum line portions may also be of importance. A particularly advantageous device is obtained if the first vacuum line portion has a maximum capacity of approximately 3500 cm3/s and/or if the second vacuum line portion has a maximum capacity of approximately 12000 cm3/s.
The invention may be applied in particular to a device comprising a milking robot with a robot arm for connecting a teat cup to a teat, at least one individual buffer vessel being disposed on or in the robot arm.
An embodiment of a device according to the invention is characterized in that each teat cup is provided with a teat cup liner forming a pulse chamber in the teat cup, in that the device is provided with a pulsator unit for generating a pulsation vacuum in a pulse chamber, with a control device provided with software for controlling the functioning of the vacuum unit or the pulsator unit in such a way that all udder quarters will be milked-out according to a predetermined chronological order, in particular at least substantially simultaneously. Due to the fact that the milking intensity is controlled in such a way that all udder quarters will be milked-out according to a predetermined chronological order, the milking can take place in an animal-friendly way. In some devices for automatically milking an animal it is customary that after the milking another treatment takes place. The performance of such a post-treatment cannot always take place immediately after the milking because, for the milking of the other udder quarters, equipment may be required that makes the post-treatment difficult, if not impossible. In such cases, a teat of a milked-out udder quarter can be post-treated only when all other udder quarters have been milked-out, which may lead sometimes to a long waiting time for the post-treatment. This may have harmful effects for the relevant udder quarter, for example in relation to its health and the health of the animal. By controlling the relevant components, according to the invention, in such a way that the udder quarters will be milked-out according to a predetermined chronological order, the milking can be optimally tuned to the further treatments of the teats, so that the animal is milked in a beneficial manner (by which is also meant a medically safe manner). It is pointed out here that a short waiting time before a teat of a milked-out udder quarter is post-treated is not harmful in many cases.
For the purpose of monitoring the progress of the milking and also monitoring the health of the animal, a device according to the invention may be provided with at least one milking parameter meter for determining, during milking, per udder quarter a value of a milking parameter, a control device controlling the milking of each udder quarter by means of the milking vacuum unit or the pulsator unit at least partially with the aid of the determined value of the milking parameter. Here it is advantageous if the milking parameter meter can be connected to the control device for supplying to the control device data in relation to the value of the milking parameter, the control device controlling the functioning of the milking vacuum unit or the pulsator unit per udder quarter with the aid of the data in relation to the value of the milking parameter.
In particular if the milking parameter meter comprises a quarter milking duration meter for determining the quarter milking duration per udder quarter, and if the device is provided with a calculating device for determining an expected quarter milking duration from historical quarter milking durations, the milking intensities for the different udder quarters can be adjusted prior to the milking.
The milking intensity is adjusted in particular by controlling the functioning of the milking vacuum unit or the pulsator unit per quarter.